1991 240 fuel evap. system leak

[faof2]

I just failed the smog test because the functional test failed - everything else was OK. As I understand it, air pressure was applied to the gas filler tube and checked later. It did not hold the pressure, which suggests there is a leak in the hose between the fuel tank and the charcoal canister, or perhaps elsewhere. I plan to check the fuel line underneath to see if there is a cracked hose. Can someone suggest a methodical way to approach this issue? Is there a (inexpensive) way to force smoke into the system to see where the smoke leaks out?
Thanks in advance for any help you may offer.
Faof2

[snippits75]

Check the big evap hose that comes off the throttle body down to the canister. Not sure if that will cause a fail, but it causes a vacuum leak.